JERUSALEM - Mitt Romney made an unannounced trip to one of the holiest sites in Judaism, the Western Wall, on Sunday, as the presumptive GOP nominee continued his week-long overseas trip.

Romney, joined by his wife, Ann, and son Josh, along with a bevy of aides, was escorted by American and Israeli security through a throng of well-wishers, press and worshippers gathered at the wall on Tisha B'av, considered the saddest day on the Jewish calendar.

Several top Romney donors were also seen at the wall, escorted by aides. A contingent of Romney donors have traveled here for a Monday fundraiser at a Jerusalem hotel.

Romney was shown a diagram of the second Temple, of which the wall is the only remnant.  The destruction of the second Temple by Roman forces nearly 2000 years ago is one of the events mourned on this day, contributing to big crowds gathered there Sunday.

The Rabbi of the Western Wall read Romney a passage, and Romney placed his hand on the wall and appeared to pray. Ann Romney prayed at a separate section of the wall reserved for women. In keeping with tradition, both Mitt and Ann Romney wrote personal messages or prayers on pieces of paper and tucked them into cracks in the wall. An aide said it would not be appropriate to disclose what the couple wrote.

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As the Romneys left the wall amidst a crowd of people, Mitt Romney reached out and shook hands with supporters, and many Israelis shouted political messages at him as he passed.

“Mitt Romney! God will make you president because you came to Israel!” one man shouted.

Jason Reed / Reuters

U.S. Republican Presidential candidate Mitt Romney visits the Western Wall, Judaism's holiest prayer site, during prayers marking Tisha B'Av in Jerusalem's Old City, Sunday.

"Free Jonathan Pollard," shouted several other men, referring to an American citizen convicted of spying for Israel, whose case has caused some friction between the two closely allied nations.

Earlier in the day, Romney met with Israeli leaders including Prime Minister Benjamin Netanyahu and Israeli president Shimon Peres. On Sunday night, Romney is due to deliver a speech on the importance of the American-Israeli alliance from Jerusalem, where he will be introduced by the city's mayor.

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Romney aides said the speech would focus heavily on the importance of the alliance, and the shared values that undergird it.

Excerpts released by the campaign indicate it would also address anxieties over the dangers posed to Israel and the world by a nuclear-armed Iran, which a Romney adviser earlier said was an "existential threat" to Israel, adding that a Romney administration would "respect" a unilateral Israeli effort to eliminate Iran's nuclear program if sanctions and other peaceful options failed.

"Today, the regime in Iran is five years closer to developing nuclear weapons capability," Romney was expected to say in his remarks. "Preventing that outcome must be our highest national security priority."

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Jason Reed / Reuters

U.S. Republican presidential candidate Mitt Romney meets Israel's Prime Minister Benjamin Netanyahu in Jerusalem, Sunday.

JERUSALEM - Mitt Romney would “respect” Israel's use of military force to stop Iran from developing a nuclear weapon, a senior aide said on Sunday as the Republican presidential candidate began his visit to Jerusalem.

"If Israel has to take action on its own, in order to stop Iran from developing that capability, the governor would respect that decision," Romney's senior national security aide Dan Senor told reporters traveling with the candidate.

While stopping short of endorsing a preemptive military attack, the comment seemed to differ with President Barack Obama's attempts to convince Israel to avoid any such move.

Gov. Romney’s first meeting was Israel's Prime Minister, Benjamin Netanyahu, who greeted him as a “personal friend and friend of Israel.”

Shaking hands underneath U.S. and Israel flags, the pair signaled that Iran would be top of the agenda in their discussions.

Netanyahu said: "We have to be honest and say that all the sanctions and diplomacy so far have not set back the Iranian program by one iota. And that's why I believe that we need a strong and credible military threat coupled with the sanctions to have a chance to change that situation."

Later, Gov. Romney and his wife Ann visited the city's Western Wall.

Sunday’s comments came as a senior Israeli official denied a newspaper report that President Barack Obama's national security adviser had briefed Netanyahu on a U.S. contingency plan to attack Iran should diplomacy fail to curb its nuclear program.

The Israeli liberal Haaretz daily on Sunday quoted an unnamed U.S. official as saying the adviser, Thomas Donilon, had described the plan over dinner with Netanyahu earlier this month.

"Nothing in the article is correct. Donilon did not meet the prime minister for dinner, he did not meet him one-on-one, nor did he present operational plans to attack Iran," the senior official, who declined to be named given the sensitivity of the issue, told Reuters.

Reuters contributed to this report.

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